On the eve of the Tour de Primes 2010, we are happy to announce that PrimeGrid is partnering with Seventeen or Bust to help solve the Sierpinski problem! This finally brings PrimeGrid full circle with SoB/PSP primality testing as well as combined sieving. Special thanks to Louis Helm of Seventeen or Bust for helping to make this collaboration possible! For more details on the new search, please see this forum thread.